0.IJACT_표지 International Journal of Advanced Culture Technology Vol.4 No.1 1-9 (2016) http://dx.doi.org/10.17703/IJACT.2016.4.1.1 Potential of Agricultural Residues for Small Biomass Power Generation in Thailand Thakrit Panklib 1 1 Siam Technology College, Bangkok, Thailand Abstract The demand for energy in Thailand has been continually increasing as the economic and social country grows. Approximately 60% of Thailand’s primary energy is imported, mostly petroleum products. In 2008 Thailand’s total energy consumption was 80,971 ktoe and the net price of energy imported was up to 1,161 billion Baht which is equivalent to 12.8% of GDP at the current price. The energy consumption or energy demand has been growing at an annual compounded growth rate of 6.42% and the peak electric power demand and electricity consumption was recorded at 22,568 MW and 148,264 GWh and grew at a rate of 7.0% and 7.5% per annum during the period from 1989 to 2008. The gross agriculture production in 2008 was recorded at 135.4 Mt which represents agriculture residue for energy at 65.73 Mt, which is equivalent to energy potential of about 561.64 PJ or 13,292 ktoe an increase in average of 5.59% and 5.44% per year respectively. The agricultural residues can converted to 15,600 GWh/year or 1,780 MW of power capacity. So, if government sector plan to install small biomass gasification for electricity generation 200 kW for Community. The residue agricultural is available for 8,900 plants nationwide. The small biomass power generation for electricity generation not only to reduce the energy imports, it also makes the job and income for people in rural areas as well. This paper’s aim is to report the energy situation in Thailand and has studied 5 main agricultural products with high residue energy potential namely sugarcane, paddy, oil palm, cassava, and maize appropriate for small electricity production. These agricultural products can be found planted in many rural areas throughout Thailand. Finally, discuss the situation, methods and policies which the government uses to promote small private power producers supplying electricity into the grid. Keywords: biomass, agricultural residues, energy potential, gasification 1. INTRODUCTION The total energy consumption in Thailand has been continually increasing. Most of the energy Thailand uses is imported such as petroleum products. Although Thailand can provide some of its own energy IJACT 16-1-1 Manuscript Received: Dec. 10, 2015 / Revised: Dec. 23, 2015 / Accepted: Jan. 10, 2016 Corresponding Author: drthakrit@gmail.com Tel, +66-2-878-5000 Fax: +66-2-878-5002 Siam Technology College, Bangkok, Thailand 2 International Journal of Advanced Culture Technology Vol.4 No.1 1-9 (2016) recourses such as natural gas and crude oil, the domestic energy recourses are not sufficient because of the increasing demand and the limitation of these energy resources. Over 80% of the total energy consumption of the country was absorbed by three main economic sectors namely the power, transport, and manufacturing sectors. Electric power is one of the major input factors in economic development. The process requires a lot of energy. When fuel prices increase the power price is increased accordingly. Use of alternative energy or renewable energy in the country is essential. Thailand is an agricultural country. Agriculture is a nationwide distribution. At present, biomass can be used to generate electricity from small electricity generation facilities. It is an effective way of eliminating agricultural waste and another way to reduce fossil fuel use. Now there are many supports from the government for small electricity producers such as the Small Power Producer and Very Small Power Producer Programs (SPP and VSPP) that allows selling the power to the grid under long term contracts, providing an “adder” on top of the normal tariff, soft loans, investment subsidies, etc. Currently the demand for electricity is increasing continuously but large power plants are difficult to build because of the local people’s opposition. While a small biomass power plant uses less space for installation, the life cycle of the biomass is relatively short and the process is not complicated, the local people can manage them by themselves. Small biomass power plants are another way to solve the energy crisis in future. Is important to reduce energy imports and reduce greenhouse gas emissions to the atmosphere as well. This paper’s aim is describing the energy situation in Thailand, the potential of biomass energy from agricultural residue appropriate for small electricity production, and the current policies of the government for promotion of power production for small power producers, which use biomass and renewable energy as the fuel to produce the electricity. 2. ENERGY AND ELECTRICITY SITUATION IN THAILAND Approximately 60% of Thailand’s primary energy is imported, mostly petroleum products. Thailand can provide some of its own energy resources, such as natural gas, crude oil from the Gulf of Thailand and lignite from the Northern part of country, but these domestic energy resources are not sufficient because of the demand for energy has been continually increasing and the limitation of its energy resources. In 2008 Thailand’s total primary energy consumption was 80,971 ktoe [1]. Energy consumption is one of the major input factors in economic development. To support economic growth and meet energy requirements in the future, alternative energy resources are needed. Year 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 E n e rg y c o n s u m p ti o n ( k to e ) 0 20x103 40x103 60x103 80x103 100x103 Energy production Energy import Figure 1. Energy consumption in Thailand Potential of Agricultural Residues for Small Biomass Power Generation in Thailand 3 Figure 1 shows the energy consumption in Thailand during the period from 1989 to 2008. The energy consumption or energy demand has been growing at an annual compounded growth rate of 6.42%. The energy consumption is the sum of energy import and energy production which has been growing at an annual compounded growth rate of 7.49% and 6.53% per annum respectively from 1989 to 2008. Over 80% of the total energy consumption of the country was absorbed by three main economic sectors namely the power, transport, and manufacturing sectors. The economic condition and the world oil prices have pushed Thailand’s net energy import to 1,161 billion Baht in 2008 equivalent to 12.8% of GDP at current price [2] as shown in Figure 2. Year 1992 1994 1996 1998 2000 2002 2004 2006 2008 V a lu e o f E n e rg y I m p o rt ( B il li o n B a h t) 0 200 400 600 800 1000 1200 1400 E n e rg y I m p o ry / G D P ( % ) 0 2 4 6 8 10 12 14 Value of Energy Import % Energy Impory / GDP Figure 2. Value of energy import and percent of energy import/GDP Year 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 E le c tr ic it y C o n s u m p ti o n ( G W h ) 20x103 40x103 60x103 80x103 100x103 120x103 140x103 160x103 180x103 P e a k D e m a n d ( M W ) 0 5000 10000 15000 20000 25000 GWh MW Figure 3. Peak electric demand and consumption Electric power is one of the major input factors in economic development. Figure 3 shows the electricity consumption and peak electric power demand in Thailand from 1989 to 2008. In 2008 the peak electric power demand and electricity consumption was recorded at 22,568 MW and 148,264 GWh and peak electric power demand and electric consumption grew at a rate of 7.0% and 7.5% per annum from 1989 to 2008 respectively. Electric consumption will be continued increasing occurring in the power demand. It was observed that the electricity consumption and peak electric power demand decreased sharply because of the economic crisis during 1998 and 1999. Electricity forecasting has become one of the most important aspects 4 International Journal of Advanced Culture Technology Vol.4 No.1 1-9 (2016) of electricity utility planning and it’s very important today that we are planning to use alternative energy or renewable energy for the country’s future. 3. POTENTIAL OF BIOMASS ENERGY FROM AGRICUTURAL RESIDUAL Thailand is one of the world leaders in agricultural production. Biomass resources, especially agricultural residues, are abundant in the country. Sajjakulnukit et al. [3] studied biomass residues from 10 main agricultural residues which possess energy potential. In 1997 the country’s total agricultural waste was 61 million tons. The study further estimated an amount of 41 million tons of biomass residues, which is equivalent to about 426x109 MJ of energy, was unused. Another independent study by EC-ASEAN COGEN Program estimated that energy potential from 4 main agricultural residues, namely bagasse, rice husk, palm oil wastes, and wood residues, was 11,200 GWh/yr or 2985 MW of power capacity [4]. There are several other agricultural residues in the country that can also be used for energy. This paper has studied 5 main agricultural products with high residue energy potential namely sugarcane, paddy, oil palm, cassava, and maize, planted in rural areas, and appropriate for small electricity producer. The energy potential estimation was performed based on residue product ratio (RPR) and as received calorific values as shown in Table I. Table 1. RPR, calorific values and factor of agricultural residues Product Residue RPR Surplus LHV (MJ/kg) Residue Energy availability factor (as received) weight factor potential factor Sugarcane Bagasse 0.250 0.207 6.430 0.350 2.364 Top & trash 0.302 0.986 6.820 Paddy Husk 0.230 0.469 12.850 0.414 4.086 Straw (top) 0.447 0.684 8.830 Oil palm Empty bunches 0.428 0.584 16.440 3.108 28.675 Fiber 0.147 0.134 16.190 Shell 0.049 0.037 17.000 Frond 2.604 1.000 7.970 Male bunches 0.233 1.000 14.860 Cassava Stalk 0.088 0.407 16.990 0.036 0.609 Maize Corn cob 0.250 0.670 16.630 0.168 2.786 *Sources: Bhattachaya et al. (1989); DEDP (1992, 1994, 1995); Black and Veatch (1999). Residue production ratio is the ratio of the amount of residue generated to the total amount of agricultural product produce and surplus availability factor is the ratio of surplus (presently wasted) amount to the amount of residue generated. Most calorific values or low heating value (LHV) were obtained from the tests conducted in the laboratories of the Department of Energy Development and Promotion (DEDP) of Thailand. The residue weight factor and energy potential factor are used to convert gross weight of agricultural products to residue weight and energy potential, the example in case of sugarcane, residue weight factor = (RPRbagasse x surplus availability factorbagasse) + (RPRtop & trash x surplus availability factortop & trash) and energy potential factor = (RPRbagasse x surplus availability factorbagasse x LHVbagasse ) + (RPRtop & trash x surplus availability factortop & trash x LHVtop & trash). In 2008 the gross agriculture production namely paddy, maize, cassava, sugarcane and oil palm was recorded at 135.4 Mt. The residues available for energy and energy potential of agricultural residues are Potential of Agricultural Residues for Small Biomass Power Generation in Thailand 5 65.73 Mt and 561.64 PJ or 13,292 ktoe respectively. Figure 4 shows the trend of each product in Thailand. The agricultural production of paddy, maize, cassava, sugarcane and oil palm increases in average of 1.5%, 0.27%, 1.1%, 5.1%, 12.98% and 2.99 % per year respectively and the total of production increases in average of 3% per year. Table II shows each type of agricultural production, Table III shows a residue available for energy, Table IV shows energy potential and Table V shows the summary of estimate agricultural residues and energy potential from 1989 to 2008. The total of agricultural residues available for energy and energy potential are increases in average of 5.59% and 5.44% per year as shows in Figure 5. The information from status of biomass potential in 2007 [13], there are many types of biomass with more than 50% non-exploited. So, there are 5 main agricultural residues about 67.7 Mt. The non-exploited residue available for energy and energy potential are 32.87 Mt and 280.82 PJ. In case of small electricity generation, it is assumed that the average LHV is 18 MJ/kg. At full generation rate use in a gasifier/gas engine generator, giving an overall efficiency of conversion to electricity of about 20%, this takes no account of the potentially useful heat available from the gasifier/gas engine [14]. The agricultural residues can converted to 15,600 GWh/year or 1,780 MW of power capacity. So, if the Thailand government is having planned to install small biomass gasification for electricity generation 200 kW for Sub-district Administrative Organization (SAO). The residue agricultural is available for 8,900 plants nationwide. Year 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 P ro d u c ti o n ( M t) 0 20 40 60 80 100 Paddy Maize Cassava Sugarcane Oil palm Figure 4. The trend of each agricultural product in Thailand in 1989 to 2008 Year 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 E n e rg y p o te n tia l (P J) 0 200 400 600 R e si d u e a va ila b le fo r e n e rg y (M t) 0 10 20 30 40 50 60 70 PJ Mt Figure 5. Thailand agricultural residues and energy potential in 1989 to 2008 6 International Journal of Advanced Culture Technology Vol.4 No.1 1-9 (2016) Table 2. Production of agriculture in 1989 to 2008 Year Production (Mt) Total Paddy Maize Cassava Sugarcane Oil palm (Mt) 1989 18.48 4.39 24.26 38.00 1.08 86.21 1990 14.90 3.72 20.70 33.62 1.18 74.12 1991 17.52 3.79 19.71 40.95 1.31 83.28 1992 17.30 3.67 20.36 47.95 1.32 90.60 1993 16.48 3.33 20.20 40.29 1.83 82.13 1994 18.16 3.97 19.09 37.82 1.92 80.96 1995 17.73 4.15 16.22 50.60 2.25 90.95 1996 17.78 4.53 17.39 57.97 2.61 100.29 1997 18.79 3.83 18.08 56.39 2.58 99.67 1998 18.66 4.62 15.59 43.46 2.52 84.86 1999 19.02 4.29 16.51 50.33 3.41 93.55 2000 19.79 4.47 19.06 54.05 3.34 100.72 2001 22.41 4.50 18.40 49.56 4.10 98.96 2002 21.57 4.26 16.87 60.01 4.00 106.71 2003 23.14 4.25 19.72 74.26 4.90 126.27 2004 22.65 4.34 21.44 65.00 5.18 118.61 2005 23.54 4.09 16.94 49.59 5.00 99.16 2006 22.84 3.92 22.58 47.66 6.72 103.72 2007 23.31 3.89 26.92 64.37 6.39 124.87 2008 23.24 4.25 25.16 73.50 9.27 135.41 Table 3. Residues available for energy in 1989 to 2008 Year Residue available for energy (Mt) Total Paddy Maize Cassava Sugarcane Oil palm (Mt) 1989 7.64 0.74 0.87 13.28 3.37 25.90 1990 6.16 0.62 0.74 11.75 3.67 22.95 1991 7.25 0.64 0.71 14.31 4.09 26.98 1992 7.16 0.62 0.73 16.76 4.10 29.36 1993 6.82 0.56 0.72 14.08 5.68 27.87 1994 7.51 0.66 0.68 13.22 5.98 28.06 1995 7.33 0.70 0.58 17.68 7.01 33.30 1996 7.35 0.76 0.62 20.26 8.12 37.12 1997 7.77 0.64 0.65 19.71 8.01 36.78 1998 7.72 0.77 0.56 15.19 7.84 32.09 1999 7.87 0.72 0.59 17.59 10.61 37.38 2000 8.18 0.75 0.68 18.89 10.39 38.90 2001 9.27 0.75 0.66 17.32 12.73 40.74 2002 8.92 0.71 0.60 20.98 12.44 43.65 2003 9.57 0.71 0.71 25.95 15.24 52.18 2004 9.37 0.73 0.77 22.72 16.11 49.69 2005 9.74 0.69 0.61 17.33 15.55 43.91 2006 9.45 0.66 0.81 16.66 20.87 48.44 2007 9.64 0.65 0.96 22.50 19.86 53.62 2008 9.61 0.71 0.90 25.69 28.82 65.73 Potential of Agricultural Residues for Small Biomass Power Generation in Thailand 7 Table 4. Energy potential in 1989 to 2008 Year Energy potential (PJ) Total Paddy Maize Cassava Sugarcane Oil palm (PJ) 1989 75.49 12.24 14.76 89.81 31.10 223.41 1990 60.89 10.37 12.60 79.46 33.88 197.19 1991 71.58 10.56 11.99 96.78 37.69 228.60 1992 70.70 10.23 12.39 113.34 37.78 244.43 1993 67.35 9.27 12.29 95.23 52.44 236.58 1994 74.20 11.05 11.62 89.40 55.13 241.39 1995 72.44 11.57 9.87 119.59 64.64 278.10 1996 72.65 12.63 10.58 137.02 74.88 307.77 1997 76.77 10.67 11.00 133.29 73.91 305.65 1998 76.25 12.86 9.49 102.73 72.34 273.68 1999 77.70 11.94 10.04 118.96 97.87 316.51 2000 80.85 12.46 11.60 127.76 95.86 328.53 2001 91.56 12.53 11.19 117.14 117.47 349.90 2002 88.12 11.86 10.26 141.84 114.74 366.83 2003 94.55 11.84 12.00 175.51 140.58 434.49 2004 92.54 12.09 13.05 153.62 148.59 419.90 2005 96.18 11.40 10.31 117.20 143.45 378.54 2006 93.32 10.91 13.74 112.64 192.56 423.18 2007 95.24 10.84 16.38 152.13 183.23 457.82 2008 94.94 11.84 15.31 173.73 265.83 561.64 Table 5. Summary of agricultural residues and energy potential in 1989 to 2008 Year Residue available Energy potential for energy (Mt) (PJ) (ktoe) 1989 25.90 223.41 5,287.29 1990 22.95 197.19 4,666.84 1991 26.98 228.60 5,410.27 1992 29.36 244.43 5,784.86 1993 27.87 236.58 5,599.04 1994 28.06 241.39 5,712.91 1995 33.30 278.10 6,581.81 1996 37.12 307.77 7,283.78 1997 36.78 305.65 7,233.62 1998 32.09 273.68 6,477.07 1999 37.38 316.51 7,490.77 2000 38.90 328.53 7,775.15 2001 40.74 349.90 8,280.91 2002 43.65 366.83 8,681.65 2003 52.18 434.49 10,282.82 2004 49.69 419.90 9,937.52 2005 43.91 378.54 8,958.81 2006 48.44 423.18 10,015.15 2007 53.62 457.82 10,834.97 2008 65.73 561.64 13,292.17 8 International Journal of Advanced Culture Technology Vol.4 No.1 1-9 (2016) 4. CONCLUSIONS Due to the current energy crisis, energy electricity demand and fuel prices continually increasing every year and the government’s issuance of policies to promote energy efficiency and renewable energy, it can be seen that biomass-based power generation seems to be quite possible in both the technological aspects and the potential of biomass. However, for sustainable achievement, the Thai government does not only create confident mechanisms but also continually encourages the IPPs and SPPs with power purchase agreements, incentive investments, as well as research for new pilot plants. Small electricity production from biomass agricultural residue is one solution to solve the domestic demand for the electricity in the future. It is feasible because small biomass power plants can be installed throughout the country, the local people can manage them by themselves and agricultural residues are plentiful in rural areas. In addition it would considerably decrease the burning of our forests and the disposal of agricultural residue saving the environment from SO2 and NOX emissions emitted into the atmosphere. Although energy policies adopted by the government are in the right direction, the pace of implementation is slow. It is very important for the government to disseminate information through public campaign to educate the public about alternative energy. 5. REFERENCES [1] Bhattachaya, S. C., Shrestha, R. M., and Ngamkajurnvivat, S. 1989. Potential of biomass residue availability: The case of Thailand. Energy Sources 11:201–216. [2] Black & Veatch. 1999. Thailand biomass-based power generation and cogeneration: Small rural industries (progress report). Bangkok, Thailand: Black & Veatch. [3] Center for Agricultural Information (CAI). 2009. Agricultural statistics of Thailand crop year 2008. Bangkok, Thailand: Center for Agricultural Information. 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